UC San Diego innovator in data storage technologies elected to National Academy of Engineering

By Liezel Labios

Back in 1956, IBM built the first disk drive. It was the size of two refrigerators and held a total of five megabytes—enough storage capacity to handle about 30 seconds of video. That’s a stark contrast to today’s hard drives, which can hold tens of terabytes of data and fit in the palm of your hand.

Eric Fullerton

One of the key innovators who helped drive this remarkable evolution is Eric Fullerton, a professor of electrical and computer engineering and nanoengineering at the University of California San Diego. In February 2018, Fullerton was elected to the National Academy of Engineering “for invention and development of multilayer, high-density magnetic recording media.”

Fullerton joined the UC San Diego Jacobs School of Engineering faculty in 2007 after years of working in industry at both IBM and Hitachi Global Storage Technologies. In 2011, he began serving as the Director of the UC San Diego Center for Memory and Recording Research (CMRR), one of the world’s leading institutions for research on storage and memory technologies including magnetic recording.

Fullerton’s research impacts are broad and include efforts to develop cutting-edge nanotechnologies to build hard disk drives and non-volatile memories that can store data at unprecedented levels. As an affiliate of the Qualcomm Institute at UC San Diego, Fullerton is a committee member of the San Diego Nanotechnology Infrastructure and a leading researcher in the area of nanomagnetics for Nano3, a nanotechnology facility at QI.

“Eric Fullerton’s research accomplishments in magnetic recording media have had deep impact on the industry,” said Albert P. Pisano, dean of the UC San Diego Jacobs School of Engineering. “Eric is also a fantastic leader, and his contributions as Director of the Center for Memory and Recording Research are stellar. He has been instrumental in attracting and engaging with industry sponsors, current and future academic partners, funding agencies and a long and distinguished list of research affiliates.”

Higher density hard drives

Prior to Fullerton's advances in the engineering of multilayer magnetic materials, areal density of hard disk drives was stuck at about 25 billion bits per square inch. It has now grown to an astounding 1.3 trillion bits per square inch.

“It is not an exaggeration to say that Eric Fullerton’s synthesis, characterization and optimization of novel magnetic multilayer materials saved the hard disk drive industry—not once, but twice—during the early part of this millennium,” said Paul Siegel, a professor of electrical and computer engineering at UC San Diego and former CMRR Director.

The first breakthrough came in 1999 while Fullerton was a research scientist at IBM and Hitachi. He helped invent a new type of magnetic media called antiferromagnetically-coupled (AFC) media, otherwise known as “pixie-dust” media for their seemingly magical ability to improve hard disk drive performance. AFC media consist of a three-atom-thick layer of the element ruthenium sandwiched between two magnetic layers. Their invention made it possible for hard disk drives to store 100 billion bits of data per square inch of disk area by counteracting the superparamagnetic effect, which occurs when magnetic regions on a hard disk become too small to retain data. Data storage experts had foreseen this as an insurmountable obstacle to sustained exponential growth in the areal density of hard disk drives.

Fullerton’s advance made it possible for the upward arc of data storage capacity to progress, even as the devices themselves continued to become smaller. “This novel approach to recording media design literally changed the course of the entire data storage industry, becoming the standard in hard disk drive technology,” Siegel said. The first consumer application of AFC media was in IBM’s Travelstar hard drive products in 2001. Later at Hitachi, Fullerton continued his work on AFC technology, developing laminated AFC media, in which an additional magnetic layer enabled further gains in storage densities.

Another breakthrough occurred in 2001, when Fullerton pioneered the development of exchange-coupled composite (ECC) materials, which were also instrumental in enabling the exponential growth of hard disk drive storage densities. ECC materials consist of alternating layers of magnetically switchable materials that help write the data and hard-to-switch materials that store the data. This combination made it possible to store more bits on magnetic recording media while keeping them thermally stable. ECC materials have become the industry standard in perpendicular magnetic recording.

Faster and energy-efficient data storage

Developing high-density storage technologies isn’t Fullerton’s only area of expertise. He is also working to make hard drives run faster and consume less energy.

“As a scientist, Eric has an incredible ability to keep making major impacts in new areas,” said Vitaliy Lomakin, a professor of electrical and computer engineering at UC San Diego and Assistant Director of CMRR. For example, in recent years, the Fullerton research group has become “the leader in the area of all-optical switching of magnetic materials, demonstrating experimentally that just using light, without any magnetic field, allows switching magnetic domains in ferromagnets. This contribution opens a path to a new approach for information storage and processing,” Lomakin added.

In 2014, Fullerton’s research group at UC San Diego published a paper in the journal Science showing that it is possible to switch magnetic bits using polarized light. This is significantly faster and less power-hungry than the process in traditional magnetic storage devices, in which magnetic bits are switched using magnetic fields. This advance has the potential to “significantly simplify the design and improve the speed of magnetic recording,” Fullerton said.

As a faculty member of CMRR and the Sustainable Power and Energy Center at UC San Diego, Fullerton is focused on developing ultra-low power information storage, memory and processing components aimed at dramatically lowering the energy consumption of information technologies. His approach in this area is inspired by the human brain, which he describes as a computer developed in an energy-starved environment. “The human brain is designed to do an enormous amount of calculations at an incredibly low amount of power,” he said. The brain uses low energy ion transport processes to both store and process information. According to Fullerton, materials being developed for ion-based energy storage might also be used for low-energy information technologies.

Awards and honors

Fullerton has co-authored more than 320 papers in peer-reviewed journals and holds 51 U.S. patents, including a patent selected as one of the “Five Patents to Watch” in 2001 by MIT Technology Review. To date, his publications in the scientific and patent literature have received more than 19,000 citations. He has been honored with various prestigious awards including: